Pretreatment echogenicity of colorectal liver metastases predicts survival after hepatic cryotherapy.

Abstract

There is currently no knowledge of the prognostic value of echogenicity of colorectal liver metastases in patients receiving no treatment, hepatic cryotherapy, or any other treatment modality. We sought to determine whether differences in echogenicity of colorectal liver metastases predict prognosis after hepatic cryotherapy. Between April 1990 and May 1997 the echogenicity of liver metastases was assessed intraoperatively in 48 patients undergoing cryotherapy for in situ destruction of colorectal liver metastases, with use of an Aloka machine with a 5-MHz scanner. Survival time was calculated by the Kaplan-Meier method, and the prognostic value of echogenicity and several other possible prognostic factors was tested with the log-rank test. Thirty-three patients were found to have hyperechoic metastases. These patients had a favorable outcome, with a median survival time of 50 months, as compared with a median survival time of 24 months in the 15 patients with hypoechoic metastases (P = 0.0074). Regarding the remaining prognostic factors that were tested, only age less than 51 years, absence of involved nodes at primary resection, small diameter of liver metastases, and low preoperative serum carcinoembryonic antigen levels were associated with a favorable outcome. We believe that this is an original description of the prognostic importance of echogenicity of colorectal liver metastases. Differences in echogenicity may be related to tumor biology. This will be addressed in further studies.